Early Justice sounds like a mad disco riding on rollercoaster rails made of serrated knives, and while that's certainly not a bad thing for the newest generation of dance music fans, it can be grating for the rest of us. In a welcome change of pace from their frantic debut, the uber-French house duo's latest album saw Xavier and Gaspard dip into borderline yacht-rock territory to show off their apparent knack for melody. Last night to close out Lollapalooza, the DJ superstars drew from both † and Audio, Video, Disco albums to create a chopped up megamix of their tracks. Unsurprisingly, it's the same approach their heroes Daft Punk took to their now-legendary Coachella appearance in 2006.

Launching into their set with appropriately titled "Genesis," a tired-looking but excited crowd was ready to dance off the turbulent weekend's frustrations and triumphs, waiting for huge bass drops that came only intermittently. The metallic guitar chords of "Helix" rang out and constituted a definite high point of the set, after which the band's hits got the slice-and-dice treatment. The entire hour was a Justice career flashback, pockets of tracks coming up for their time in the spotlight before getting folded back into the larger framework. It was like being quickly ushered through an entire menu rather than allowed to enjoy carefully selected meal.

That's not to say the show wasn't the spectacle people expected -- the stage setup showcased Justice's ever-present crucifix symbolism and the booth appeared to be a soundboard turned outward, buttons flashing and pulsing with the music. About a third of the way in, Xavier stepped out into the front of the stage and simply raised one arm, the park falling silent in suspense except for Jack White's faint rasps from the other end. Something was about to happen -- would it be fireworks or other crazy pyrotechnics? Instead, the band made their point as the familiar "We! Are! ... Your Friends!" vocal hook seared its way through the tens of thousands of fans. Justice was acknowledging their breakthrough jam, and Lolla fans did in turn as fists shot into the air with every word.

The closing set was an appropriate finale to the festival, though parts felt like teasers to something enormous that never really came. The younger concert goers were raised on dubstep drops and the older generation on disco synths, and while they both likely came away feeling happy, there were probably more than a few who felt like there was something left in the air aside from smoke and foodcourt fumes.

Personal bias: I think Justice take too heavy a cue from their Daft Punk countrymen but still enjoy their music, especially newer tracks like "Helix" that show great promise for future production.

The crowd: Lots of ladies leaping by like raver gazelles armed with glow tubes (a supposed upgrade from sticks?) and frat bros with saucer eyes.

Random notebook dump: Wonder what Justice think of their American festival fans.

Overheard: 15-year-old, on a mad dash toward the stage: "Who's playing up there?" Me: Justice. Him: "I'm going the right way then!!"